They finished 25-57, the third-most losses in franchise history — they had 67 in 1996-97 and 58 in 2006-07. They lost 43 of their last 56 games and will miss the playoffs for the first time since the 2006-07 season.

“Motivation for next year,” Rajon Rondo said. “We have a lot to improve on.”

They were a patchwork team ravaged by injuries and thrown-together lineups, but players remained united in Brad Stevens’s first season as head coach.

“Things like this can splinter you pretty easily, and they stayed together pretty well as far as standing up for one another and being a team and not pointing blame,” said Stevens, who left Butler University last summer to take over for Doc Rivers.

Stevens also learned much about himself.

“The best thing I learned is that this — it’s not fun to not win,” he said. “But it doesn’t define who you are or how you go about your business. So, one of the things that I’m probably most happy about with our team is that they didn’t change necessarily who they were.

“They didn’t let the losing or the multiple losses affect them or their approach and I hope that I was the same way. So maybe that going forward, I learned a lot about the NBA game and how it’s played and it’s a different kind of basketball.”

The game itself was an afterthought. On Fan Appreciation Night, Rondo sat out with a sprained left hamstring, and Jared Sullinger (ankle), Jerryd Bayless (knee), and Kris Humphries (knee) were also sidelined.

Kelly Olynyk led the Celtics with 24 points.

Bradley Beal led the playoff-bound Wizards (44-38) with 27 points.

In the third quarter, Celtics co-owner Wyc Grousbeck went into the stands to thank the fans and Sullinger addressed them before the game, “We want to thank you for your endless support and passion throughout the whole season. Hopefully we’ll come back better next year.”

Stevens is hopeful.

“I’m not concerned that we aren’t going to strive to get better,” he said. “I think we will work. I think their work ethics are good, and I think their coach-ability is pretty good.”

For the Celtics, now begins a summer of potential “fireworks,” as Grousbeck has said.

First, they’ll wait to see how the NBA draft lottery ping-pong balls bounce May 20 in New York. The Celtics ended their season tied for the NBA’s fourth-worst record with Utah.

Both teams will split the 207 ping-pong balls that the fourth- and fifth-worst teams receive, with a random drawing deciding which team will receive the extra ball as well as the higher pick in the event that neither team ends up with a top-three pick.

For now, the Celtics and Jazz each have about a 33.7 percent chance at a top-three pick and a 10.4 percent chance at the No. 1 pick.

The Celtics have two first-round draft picks in the June 26 draft. They’ll pick no lower than eighth for the first pick, and their second pick, which they acquired in a deal with the Brooklyn Nets last summer, will be No. 17 or No. 18, depending on the outcome of a coin flip.

Beyond who will join the team via the draft, it’s unclear which players from this season’s team will be around when next season begins.

Bayless, Humphries, and Avery Bradley will become free agents, though Bradley will be restricted, meaning the Celtics can match any offer he receives.

Rondo, the longest-tenured Celtic, would like input on offseason moves.

“I think it’s deserved,” said Rondo, who was drafted by the Celtics in 2006.

“Everybody is different, every team is different. I wouldn’t mind being that guy. I’ve been that guy in a capacity the past couple years. If we needed guys to recruit or call guys on the phone, I’ve always done that as well.”

Rondo is expected to be in trade rumors this summer, and when asked if he wanted to return, he said that he answered that question a week ago.

When pressed, Rondo, who is entering the final year of his contract, said, “Next question.”

Their offseason will be full of queries.

The only certainty now is that the Celtics are on ice, and so is the Garden, which will be hosting only Bruins’ playoff games this spring, meaning the building’s Bull Gang can pack away the parquet — the 2013-14 Celtics are done.